U.S. Pat. No. 6,447,604 B1 describes a III-V nitride homoepitaxial microelectronic device structure which may be used in UV-LEDs. A thin oxide layer is grown on a (Al,In,Ga)N substrate and subsequently stripped in an alkali solution or etched off in other suitable manner just before growth. The purpose of this thin oxide layer is to getter or remove potential impurities from the substrate, and allow the first few mono layers of the substrate surface to be free of homo-epitaxial layer interrupting impurities (such as C, Si, S or O) and/or other impurities.
There is a further need to reduce impurities during the growth process of light emitting semiconductor devices in order to increase lifetime and performance of the devices.